Cup-piston construction for lubricating devices



Nov,` 16 1926.

C L C. F. HOOFER CUP PIsToN CONSTRUCTION FCR LUBRCATNG DVICES Filed Nov. 2'?, 1925 Patented Nov. `16, 1926.

Unirse STATE-s CHAnLns rianne-nml; Hoornn, orV CnICAe-o, ILLNoIs.

Cunrlsron CONSTRUCTION Application filed November My invention relates toV improvements in which the amount of timeftaken :for manufacturing the device is cut down to a minimum, because the follower cap can be screwed down as tightly as possible, and when so tightened will exert the required amount of pressure upon the Cup piston;

A further object of my invention is to provide a device of the type described in which novel means is provided for permitting the follower cap to be screwed down tightly into place to clamp the cup piston to the rod, this means preventing the cap from shearing the cup piston.

A further object of my invention is to provide a device of the type described which has novel means for preventing further movement of 'the follower cap when the cap has exerted the required amount of pressure on the cup piston,whereby a uniform product is assured. l

- Other objects and advantages will appear in the following specification, and the novel features of the invention will be particularly pointed out in theappended claims.

My inventionjis illustrated in the'accompanying drawings, forming part of this application, in whichy Figure l is a vertical section `through the device, and

Figure 2 is an enlarged view of a portion of the device partly in section.

In carrying out my invention, I provide a casing l for holding a lubricating fluid. The fluid is admitted to the `casing through a door 2 and passes through a screen 3 before it is received in the casing. A drain plug l is provided for the casing.

A plurality of plunge-rs 5 are mounted in the casing l, and I have shown one of these plungers in Figure l. Each plunger carries a piston at its upper end, and the novel denon LUBRICATING DEVICES.

27, 1925. semi No. amie.

sign of this piston construction is clearly shownlin Figure t2. A base .is screwed down upon the threadedportion- '.7 ofthe plunger rod 5, and this base is provided with a flange 8 for a purpose hereii'iafter described. A' resilient cup 9 is mounted upon the base 6 and bears against the flange 8. The thickness of the wall of the cup Vis slightly. greater than the height ofthe flange S, andit will thereforeappear th'at'tlie bot"- tom of the cup will extend slightly `al'iovethe top of the flange. I next dispose what I term a metal expand-er l() in the resilient Cup 9. This expander conforms to the interior of the cupv9, and is provided with an inwardly extendingv flange ll for overlying the top of the flange 8. The portion of the expander bearing against thelinner periphery of the cup 9 is eut up into a plurality of resilient fingers l2; .These lingers are for the purpose'of normally expanding the cup 9, as will be hereinafter described. 'v

The cup 9 and the expander l0 areloclred in place by means of a follower cap 13;" The Vside wall 14e ofthe cap is spaced from the inner surfaces of the fingers l2, thus permitting the compressed air to force its way down into the interior of the Cup, The Cap 13 when screwed into position "forces the flange 11 down upon the flange 8,' and in doing so causes the flange ll to slightly squeeze the portion of the cup 9 disposed between the flange ll and the shoulder 15 of the base 6. It will be seen that the cap may be screwed tightly into place, and yet will have no tendency to shear the cup 9; rlhis i due to the fact that there isan all-metal connection between the cap landv the'base 6. The wall ofthe cup-shapedmember' 9 is made of a predetermined thickness, and this thickness is sufficient to cause the flange ll to slightly squeeze the wall when the flange is locked in place by the nut 13.

It will be noted from Figure lower end of the plunger rod 5 is provided with a plunger head 16. A valve l? is screwed into this plunger head, and this valve is provided with a tapered portion 1S adapted to seat against a tapered portion 19 to limit the movement of the plunger rod away from the bottom of the casing, and to provide a liquid-tight closure between the liquid in the casing and the outlet nipple 20. The spring 21 extends the entire dis-- l that the tance of the plunger rod and bears against the outlet plug E22 and the base From the foregoing description of the various parts of the device, the operation thereof may be readily understood. In operation air is admitted to the compartment 23 in the manner set fortlfin my co-pending application, Serial No. 718,311, filed .lune 6, 1924. As stated in my co-pending application, this air will force the plungerI rod 5 downwardly,l and will also flow through the bore of the plunger rod. Figure 1 shows how the tapered portion 18 preveiits the top of the follower cap 13 from contacting with the screw plug 9.1!. This construction permits the air to pass through the passageway and into the bore of the plunger' rod During the downward movement of the plunger rod 5, the oil in the recess Q7 passes into thev outlet nipple 20, and this quantity of oil is then conveyed to the part to be lubricated by the compressed air.

In the first part of the specification, I pointed out the advantage of providing an all-metal connection between the follower cap 13 and the flange 8 of the base G. This construction permits the follower cap to be screwed tightly down upon the flange 11, thug bringing the flange into contact with the top of the flange 8 and causing the :flange 11 to squeeze the cup 9. The wall of the cup 9 is made of a predetermined thickness and the flange 8 permits the required amount of pressure to be exerted upon the expander to squeeze the wall of the cup 9 between the expander and the shoulder 15, and then prevent further movement of the follower cap 13 toward the base 6. In this way, the Workman vassembling the'device can screw up the follower cap as tight as possible without the possibility of shearing the cup 9. At the same time, the cup 9 and the expander 10 are locked in place and provide a leak-proof connection between the follower cap 13 and the base 6.

I claim: y l 1. In a device of the type described, a plunger rod, a base, a cup mounted on said base, an expander for said cup, and means for forcing said expander into Contact with v said base, saidycup being clamped between said expander and said base, said base determining the amount of pressure exerted by the expander upon the cup.

2. A device of the type described comprising a plunger' rod, a base mounted on said rod and having a flange, a cup carried by said base, an expander carried by said rod and bearing against said flange, and a follower cap vsecured to said rod for forcing said expander into contact with saifl flange, said cup being slightly squeezed between said expander and said base, said flange limiting the amount of force exerted by the expander upon said cup.

3. In a piston construction, a plunger rod, a base carried by the plunger rod, a resilient cup carried by the base, means for clamping the cup. to the base, and .means for preventing the shearing of the cup by the clamping means.

4.111 a piston construction, a plunger rod, a resilient cup, means for clamping said cup to said rod, and means for limiting the .force of said clamping means to prevent said clamping means from shearing the cup.

5. A cup piston construction for lubricating devices comprising ya supporting member having a threaded portion, a base carried by said threaded portion and having a. centrally disposed annular flange, a resilient cup disposed on the base and having a central opening arranged to receive said annular flange, an expander having a portion disposed in engagement with said flange and being arranged toA bear on the resilient cup, and a clamping member secured to said threaded portion forA holding said expander against said flange.

6. A piston construction for lubricating devices, comprising a supporting member having a threaded portion, a base carried by said threaded portion and. having a cen-- trally disposed annular flange, a resilient cup disposed on the base and having a central opening arranged to receive said annular flange, an expander having. a portion disposed in engagement withl said flange and being arranged to bear on the resilient cup, and a clampingfmember secured to said threaded portion for holding said expander against said flange.

CHARLES FREDERICK 'HOQFER.

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